Referring to FIG. 1, there is shown a masking paper 4 having a masking strip 1 which may be a thin systhetic resin film. It is substantially elongate, and has a determined width great enough to mask a surface or portion of an object which is not to be painted. If the masking paper 4 is used in painting the vertical wall surface of a building having a window or windows therein, the masking strip should have a substantially equal width to the height of the window or windows. As shown, the masking strip 1 is folded into several parallel pleats which run in the longitudinal direction. The strip has a relatively thick tape 2 bonded along the longitudinal margin. Specifically, as shown in FIG. 2, the tape has a pressure-sensitive adhesive layer 3 overall on the one side and is laid width wisely halfway on the longitudinal margin of the masking paper strip, leaving the other half section of the adhesive layer unconcealed.
For conveniences of carrying and handling the masking paper for application, it is to be wound as folded in a coil, as shown in FIG. 3, where the unconcealed adhesive layer in one turn lies on the opposite side surface of the tape in the next turn. The opposite side surface of the tape may be treated with silicon to keep the overlying portions untacky.
A painter may conveniently carry the masking paper roll 4 to, say, a building where he would do his operation. Unwinding the masking paper roll, he may manually extend a length of the masking paper along the width length of a window to be masked and press the unconcealed pressure-sensitive adhesive layer against the upper member of the window frame. When he has produced a desired length of the masking paper from the roll to cover the width of the window, he may cut it from the roller. The pleated portion fixed by the tape onto the upper window frame member in place can be unfolded and expanded by manually pulling the lower edge of the strip to conceal the overall surface of the window. With the window surface being thus concealed, the painter can perform the painting operation without inadvertently smearing the window portion with his paint. After finishing the painting operation, he can easily detach the masking paper by delaminating the unconcealed adhesive portion from the window frame member.